4-(4-trans-hydroxycyclohexyl)amino-2-phenyl-7H-pyrrolo[2,3d]pyrimidine is disclosed in WO 99/62518 (compound 18 on page 53) and is a selective Adenosine-1 Receptor agonist that may be used in the treatment of essential hypertension, congestive heart failure, and renal failure. During further development of said compound in the above-mentioned indications, it appeared that the compound as disclosed in WO 99/62518 has the serious drawback of a low solubility in gastrointestinal fluids.